I also submit an estimate of funds on account of pontoon and bridge trains which the exigencies of the Department of the Cumberland and this department require to be furnished at the earliest possible moment.

I am, general, very respectfully, your obedient servant,

J. H. SIMPSON,

Major of Engineers.

Brigadier General JOSEPH G. TOTTEN,

Chief Engineer Department, Washington, D. C.

OFFICE CHIEF ENGINEER, DEPT. OF THE OHIO,

Cincinnati, Ohio, September 18, 1863.

GENERAL: I have the honor to make the following report of operations in this department for August last:

DEFENSES OF CINCINNATI, COVINGTON, AND NEWPORT.

Mr. T. C. Ruggles, chief engineer in charge, reports:

The work on Fort Mitchel has been progressing the same as last month. The ditches are all excavated excepting at the northeast corner. Five guns have been remounted (at Mitchel) to correspond with to correspond with the change of grade in the fort. Platforms for solid shot and grape have been made for the batteries between Mitchel and Licking River.

The military road between the pontoon bridge and Independence turnpike is finished; also the road from Battery Coombs to Batteries Bates and Perry.

We have furnished during the month 5 men to the surveying parties between Licking River and Alexandria turnpike. The survey is finished.

FORT ROBINSON, PARIS, AND DEFENSES OF CAMP NELSON, KY.

Mr. John G. Gilliss, chief engineer in charge, reports in relation to Fort Robinson:

One-fourth of earth-work done. Revetment, one-fourth done. Magazine excavations finished; wood-work of magazine commenced; 800 days' work; average number soldiers, 50.

In relation to defenses of Camp Nelson, he reports:

Nine platform laid; two embrasures sodded; parapet of west battery raised 18 inches, of Fort Jackson 12 inches; magazine for Fort Jackson excavated; one-half square mile surveyed. Mr. Gilliss Captain Poe, chief engineer. Twenty-third Army Corps, of these works August 11, the latter accompanying this corps to East Tennessee; 800 days' work; average number of contrabands, 30.

DEFENSES OF LOUISVILLE AND NASHVILLE ROAD.

I have received no report of operations during August.

SURVEYS FOR EXTENSION OF KENTUCKY CENTRAL RAILROAD FROM NICHOLASVILLE INTO EAST TENNESSEE.

Mr. William A. Gunn, chief engineer in charge, reports:

The party on the first division completed the location from the Kentucky River Suspension Bridge to the line of Mercer and Boyle Counties the 15th August. About this time General Burnside received a communication from Mr. John A. Roebling, stating that six months would be required to build a temporary suspension bridge over the Kentucky River with capacity to transfer one car at a time, and would cost $75,000; also that it would take eighteen to build the permanent bridge.